Approximately 500,000 Americans undergo spinal surgery each year, and the instrumentation involved in these surgeries has and will continue to evolve. This evolution not only includes the advancement of the material properties of the implants themselves, but also the advancements of the surgical tools used by surgeons.
Correction of spinal instability, whether due to traumatic injury or disease, is often accomplished through spinal surgery and the use of instrumentation to reduce relative motion between two or more vertebrae. This procedure can be approached from the back (posterior), front (anterior) or by a combination of posterior and anterior approaches. Metallic instrumentation is often used to stabilize the spine. These metallic implants conventionally consist of wires, screws, hooks and rods. A metal rod is bent to match the desired curvature of the spine and is attached to the vertebra with wire, screws, or hooks to correct any deformity, thereby providing support to the spine. There are a variety of conventional surgical rod benders that can be used to shape spinal rods. Existing spinal rod benders can be broken up into two groups: table-top benders and hand-held benders.
The most commonly used hand-held bender is the French Bender, which is a cam-action rod bender that uses three points of contact for bending. The French Bender is capable of making bends up to approximately 30 degrees. To operate the French Bender the surgeon must place the rod in the desired position and then grasp two handles and bring them together. This operation resembles that of a bolt cutter and sometimes requires another individual to hold the rod in place so that the rod doesn't fall out of the desired position while the surgeon grasps the handles. Alternatively, the other individual grasps the handles of the rod bender, and the surgeon instructs the other individual where, and to what extent, the rod should be bent. This procedure is less than optimal because the surgeon often uses the device with the assistance of additional personnel. The extra communication required between the surgeon and staff produces potential inefficiencies and inaccuracies in the bending of the rod. Additionally, the action of bringing the handles of the bender together has caused surgeons to accidentally injure themselves. Another hand-held surgical bender is the In Situ Bender or Key Hole Bender, which is used to correct the curvature of the rod after it is placed into the construct of the spinal system.
A variety of conventional table-top benders are available for surgical applications. The procedure for operating these benders is a multi-step process which can be quite tedious and time-consuming—the surgeon must leave the patient's side, approach the table with the rod bender, bend the rod, and then return to the patient. This procedure is often repeated multiple times to bend the rod to the ideal shape for the patient's spine. In general, table-top benders offer greater precision (at bending angles of up to 90 degrees) and repeatability at the cost of decreased efficiency.
Thus, there is a need in the pertinent art for a hand-held bending instrument that can provide precise bends at a desired bending angle while having an ergonomic, safe, and efficient design.